Merge pull request #37 from halverneus/dev

Added CORS wildcard support.

Dockerfile

@@ -3,7 +3,7 @@
 ################################################################################
 FROM golang:1.13.1 as builder
 
-ENV VERSION 1.6.6
+ENV VERSION 1.7.0
 ENV BUILD_DIR /build
 
 RUN mkdir -p ${BUILD_DIR}
@@ -31,5 +31,5 @@ LABEL life.apets.vendor="Halverneus" \
       life.apets.url="https://github.com/halverneus/static-file-server" \
       life.apets.name="Static File Server" \
       life.apets.description="A tiny static file server" \
-      life.apets.version="v1.6.6" \
+      life.apets.version="v1.7.0" \
       life.apets.schema-version="1.0"

Dockerfile.all

@@ -1,6 +1,6 @@
 FROM golang:1.13.1 as builder
 
-ENV VERSION 1.6.6
+ENV VERSION 1.7.0
 ENV BUILD_DIR /build
 
 RUN mkdir -p ${BUILD_DIR}
@@ -21,5 +21,5 @@ LABEL life.apets.vendor="Halverneus" \
       life.apets.url="https://github.com/halverneus/static-file-server" \
       life.apets.name="Static File Server" \
       life.apets.description="A tiny static file server" \
-      life.apets.version="v1.6.6" \
+      life.apets.version="v1.7.0" \
       life.apets.schema-version="1.0"

README.md

@@ -14,6 +14,9 @@ Install from any of the following locations:
 Default values are shown with the associated environment variable.
 
 ```bash
+# Enables resource access from any domain.
+CORS=false
+
 # Enable debugging for troubleshooting. If set to 'true' this prints extra
 # information during execution. IMPORTANT NOTE: The configuration summary is
 # printed to stdout while logs generated during execution are printed to stderr.
@@ -60,6 +63,7 @@ the path to the configuration file using the command line option
 ('-c', '-config', '--config').
 
 ```yaml
+cors: false
 debug: false
 folder: /web
 host: ""

cli/help/help.go

@@ -33,6 +33,10 @@ DEPENDENCIES
     None... not even libc!
 
 ENVIRONMENT VARIABLES
+    CORS
+        When set to 'true' it enables resource access from any domain. All
+        responses will include the headers 'Access-Control-Allow-Origin' and
+        'Access-Control-Allow-Headers' with a wildcard value ('*').
     DEBUG
         When set to 'true' enables additional logging, including the
         configuration used and an access log for each request. IMPORTANT NOTE:
@@ -85,6 +89,7 @@ CONFIGURATION FILE
 
     Example config.yml with defaults:
     ----------------------------------------------------------------------------
+    cors: false
     debug: false
     folder: /web
     host: ""

cli/server/server.go

@@ -61,6 +61,12 @@ func handlerSelector() (handler http.HandlerFunc) {
 	if !config.Get.ShowListing {
 		handler = handle.IgnoreIndex(handler)
 	}
+
+	// If configured, apply wildcard CORS support.
+	if config.Get.Cors {
+		handler = handle.AddCorsWildcardHeaders(handler)
+	}
+
 	return
 }
 

cli/server/server_test.go

@@ -42,23 +42,28 @@ func TestHandlerSelector(t *testing.T) {
 		listing bool
 		debug   bool
 		refer   []string
+		cors    bool
 	}{
-		{"Basic handler w/o debug", testFolder, "", true, false, ignoreReferrer},
+		{"Basic handler w/o debug", testFolder, "", true, false, ignoreReferrer, false},
-		{"Prefix handler w/o debug", testFolder, testPrefix, true, false, ignoreReferrer},
+		{"Prefix handler w/o debug", testFolder, testPrefix, true, false, ignoreReferrer, false},
-		{"Basic and hide listing handler w/o debug", testFolder, "", false, false, ignoreReferrer},
+		{"Basic and hide listing handler w/o debug", testFolder, "", false, false, ignoreReferrer, false},
-		{"Prefix and hide listing handler w/o debug", testFolder, testPrefix, false, false, ignoreReferrer},
+		{"Prefix and hide listing handler w/o debug", testFolder, testPrefix, false, false, ignoreReferrer, false},
-		{"Basic handler w/debug", testFolder, "", true, true, ignoreReferrer},
+		{"Basic handler w/debug", testFolder, "", true, true, ignoreReferrer, false},
-		{"Prefix handler w/debug", testFolder, testPrefix, true, true, ignoreReferrer},
+		{"Prefix handler w/debug", testFolder, testPrefix, true, true, ignoreReferrer, false},
-		{"Basic and hide listing handler w/debug", testFolder, "", false, true, ignoreReferrer},
+		{"Basic and hide listing handler w/debug", testFolder, "", false, true, ignoreReferrer, false},
-		{"Prefix and hide listing handler w/debug", testFolder, testPrefix, false, true, ignoreReferrer},
+		{"Prefix and hide listing handler w/debug", testFolder, testPrefix, false, true, ignoreReferrer, false},
-		{"Basic handler w/o debug w/refer", testFolder, "", true, false, testReferrer},
+		{"Basic handler w/o debug w/refer", testFolder, "", true, false, testReferrer, false},
-		{"Prefix handler w/o debug w/refer", testFolder, testPrefix, true, false, testReferrer},
+		{"Prefix handler w/o debug w/refer", testFolder, testPrefix, true, false, testReferrer, false},
-		{"Basic and hide listing handler w/o debug w/refer", testFolder, "", false, false, testReferrer},
+		{"Basic and hide listing handler w/o debug w/refer", testFolder, "", false, false, testReferrer, false},
-		{"Prefix and hide listing handler w/o debug w/refer", testFolder, testPrefix, false, false, testReferrer},
+		{"Prefix and hide listing handler w/o debug w/refer", testFolder, testPrefix, false, false, testReferrer, false},
-		{"Basic handler w/debug w/refer", testFolder, "", true, true, testReferrer},
+		{"Basic handler w/debug w/refer w/o cors", testFolder, "", true, true, testReferrer, false},
-		{"Prefix handler w/debug w/refer", testFolder, testPrefix, true, true, testReferrer},
+		{"Prefix handler w/debug w/refer w/o cors", testFolder, testPrefix, true, true, testReferrer, false},
-		{"Basic and hide listing handler w/debug w/refer", testFolder, "", false, true, testReferrer},
+		{"Basic and hide listing handler w/debug w/refer w/o cors", testFolder, "", false, true, testReferrer, false},
-		{"Prefix and hide listing handler w/debug w/refer", testFolder, testPrefix, false, true, testReferrer},
+		{"Prefix and hide listing handler w/debug w/refer w/o cors", testFolder, testPrefix, false, true, testReferrer, false},
+		{"Basic handler w/debug w/refer w/cors", testFolder, "", true, true, testReferrer, true},
+		{"Prefix handler w/debug w/refer w/cors", testFolder, testPrefix, true, true, testReferrer, true},
+		{"Basic and hide listing handler w/debug w/refer w/cors", testFolder, "", false, true, testReferrer, true},
+		{"Prefix and hide listing handler w/debug w/refer w/cors", testFolder, testPrefix, false, true, testReferrer, true},
 	}
 
 	for _, tc := range testCases {
@@ -68,6 +73,7 @@ func TestHandlerSelector(t *testing.T) {
 			config.Get.ShowListing = tc.listing
 			config.Get.URLPrefix = tc.prefix
 			config.Get.Referrers = tc.refer
+			config.Get.Cors = tc.cors
 
 			handlerSelector()
 		})

config/config.go

@@ -14,6 +14,7 @@ import (
 var (
 	// Get the desired configuration value.
 	Get struct {
+		Cors        bool     `yaml:"cors"`
 		Debug       bool     `yaml:"debug"`
 		Folder      string   `yaml:"folder"`
 		Host        string   `yaml:"host"`
@@ -27,6 +28,7 @@ var (
 )
 
 const (
+	corsKey        = "CORS"
 	debugKey       = "DEBUG"
 	folderKey      = "FOLDER"
 	hostKey        = "HOST"
@@ -48,6 +50,7 @@ var (
 	defaultTLSCert     = ""
 	defaultTLSKey      = ""
 	defaultURLPrefix   = ""
+	defaultCors        = false
 )
 
 func init() {
@@ -65,6 +68,7 @@ func setDefaults() {
 	Get.TLSCert = defaultTLSCert
 	Get.TLSKey = defaultTLSKey
 	Get.URLPrefix = defaultURLPrefix
+	Get.Cors = defaultCors
 }
 
 // Load the configuration file.
@@ -104,6 +108,7 @@ func Log() {
 // overrideWithEnvVars the default values and the configuration file values.
 func overrideWithEnvVars() {
 	// Assign envvars, if set.
+	Get.Cors = envAsBool(corsKey, Get.Cors)
 	Get.Debug = envAsBool(debugKey, Get.Debug)
 	Get.Folder = envAsStr(folderKey, Get.Folder)
 	Get.Host = envAsStr(hostKey, Get.Host)

handle/handle.go

@@ -109,6 +109,16 @@ func IgnoreIndex(serve http.HandlerFunc) http.HandlerFunc {
 	}
 }
 
+// AddCorsWildcardHeaders wraps an HTTP request to notify client browsers that
+// resources should be allowed to be retrieved by any other domain.
+func AddCorsWildcardHeaders(serve http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+		w.Header().Set("Access-Control-Allow-Headers", "*")
+		serve(w, r)
+	}
+}
+
 // Listening function for serving the handler function.
 func Listening() ListenerFunc {
 	return func(binding string, handler http.HandlerFunc) error {

handle/handle_test.go

@@ -458,3 +458,76 @@ func TestValidReferrer(t *testing.T) {
 		})
 	}
 }
+
+func TestAddCorsWildcardHeaders(t *testing.T) {
+	testCases := []struct {
+		name        string
+		corsEnabled bool
+	}{
+		{"CORS disabled", false},
+		{"CORS enabled", true},
+	}
+
+	corsHeaders := map[string]string{
+		"Access-Control-Allow-Origin":  "*",
+		"Access-Control-Allow-Headers": "*",
+	}
+
+	for _, serveFile := range serveFileFuncs {
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				var handler http.HandlerFunc
+				if tc.corsEnabled {
+					handler = AddCorsWildcardHeaders(Basic(serveFile, baseDir))
+				} else {
+					handler = Basic(serveFile, baseDir)
+				}
+
+				fullpath := "http://localhost/" + tmpFileName
+				req := httptest.NewRequest("GET", fullpath, nil)
+				w := httptest.NewRecorder()
+
+				handler(w, req)
+
+				resp := w.Result()
+				body, err := ioutil.ReadAll(resp.Body)
+				if nil != err {
+					t.Errorf("While reading body got %v", err)
+				}
+				contents := string(body)
+				if ok != resp.StatusCode {
+					t.Errorf(
+						"While retrieving %s expected status code of %d but got %d",
+						fullpath, ok, resp.StatusCode,
+					)
+				}
+				if tmpFile != contents {
+					t.Errorf(
+						"While retrieving %s expected contents '%s' but got '%s'",
+						fullpath, tmpFile, contents,
+					)
+				}
+
+				if tc.corsEnabled {
+					for k, v := range corsHeaders {
+						if v != resp.Header.Get(k) {
+							t.Errorf(
+								"With CORS enabled expect header '%s' to return '%s' but got '%s'",
+								k, v, resp.Header.Get(k),
+							)
+						}
+					}
+				} else {
+					for k := range corsHeaders {
+						if "" != resp.Header.Get(k) {
+							t.Errorf(
+								"With CORS disabled expected header '%s' to return '' but got '%s'",
+								k, resp.Header.Get(k),
+							)
+						}
+					}
+				}
+			})
+		}
+	}
+}